body {
  background: #eee;
  font-family: sans-serif;
}

.card {
  width: 400px;
  background: #fff;
  margin: 16px auto;
}

.title {
  background: #e3f4ff;
}

.content {
  background: #e3f4ff;
}

.button-container {
  background: #e3f4ff;
}

button {
  background: white;
  border: 1px solid #eee;
}

/* SOLUTION */

/* disclaimer: duplicating the selectors here isn't best practice.
In your solution you probably put it right inside the existing selectors,
which _is_ the best practice.

We separated it out here to make it extra clear what has changed. */

.card {
  padding: 8px;
}

.title {
  margin-bottom: 8px;
  font-size: 16px;
  padding: 8px;
}

.content {
  margin-bottom: 8px;
  padding: 16px 8px;
}

.button-container {
  text-align: center;
  padding: 8px;
}

button {
  display: block;
  margin: 0 auto;
  padding: 8px 24px;
}